LEGUMINOS/E. CCXXXIII. ACACIA. 



413 



flower ; in reference to the flowers being collected into globose 

 heads on the tops of the peduncles). Leaves bipinnate, with few 

 or many pairs of pinnae, each pinna bearing few or many pairs 

 of leaflets. Flowers collected into globose heads at the tops of 

 the peduncles. 



* Prickles all stipular and straight. Legumes unarmed. Sta- 

 mens 20 or more. 



1 . Aculeidce (from aculeatus, prickly ; plants furnished with 

 stipular prickles). 



172 A. NI'TIDA (Willd. spec. 4. p. 1086.) spines twin ; leaves 

 with 2 pairs of pinnae, each pinna bearing 5 pairs of oblong leaf- 

 lets, which are narrowest at the base, and shining above, with a 

 gland between each of the pairs of pinnae ; petioles pubescent ; 

 heads of flowers pedunculate, twin. ^ . S. Native of the East 

 Indies. Mimosa nitida, Vahl. symb. 2, p. 803. Flowers poly- 

 androus. Legume unknown. 



Ainifl-leaved Acacia. Tree. 



173 A. SEYA'L (Delil. fl. aegypt. 142. t. 52. f. 2.) spines twin, 

 straight, about the length of the leaves ; leaves with 2 pairs of 

 pinnae, each pinna bearing 8-12 pairs of oblong-linear glabrous 

 leaflets ; legumes compressed, linear, falcate, acute, glabrous. 



^ . G. Native of Egypt, where it is called Sejal. Mimosa Sejal, 

 Forsk.descr. p. 177. In a specimen received byDe Candolle from 

 Sieber the branches are brown, the prickles stipular, shorter than 

 the leaves, and sometimes wanting ; the heads of flowers are 

 globose and yellow, and the legume is striated with nerves. It 

 is perhaps the same as the plant of Delile. 

 Sejal Acacia. Shrub. 



174 A. HO'RRIDA (Willd. spec. 4. p. 1082.) spines twin, about 

 equal in length to the leaves, and are glabrous, as well as the 

 leaves and branches ; leaves with 2-3 pairs of pinnae, each pinna 

 bearing 9-12 pairs of oblong obtuse leaflets, with the rib biglan- 

 dular ; heads of flowers pedunculate, axillary, usually aggregate, 

 fj . G. Native of the south of Africa and of Arabia. Mimosa 

 horrida, Lin. spec. 1505. Mimosa leucacantha, Jacq. schoenbr. 

 t. 393. Mimosa eburnea, Lam. diet. 1. p. 18. A. Capensis, 

 Burch. trav. 189. with a figure. Mimosa Orfota, Forsk. descr. 

 177. Mimosa Capensis, Burm. fl. cap. prod. 27. Pluk. phyt. 

 121. f. 4. with white spikes. Young branches almost unarmed. 

 Flowers yellow, polyandrous. Legume unknown. There is a 

 variety of this species bearing 1-3 glands on the petiole, either 

 beneath or between the pairs of pinnae. Spines in pairs, white, 

 purple at the top. 



Horrid Acacia. Clt. 1 823. Shrub. 



175 A. EBU'RNEA (Willd. spec. 4. p. 1081.) spines twin, con- 

 nate, and are, as well as the branches and leaves, glabrous ; 

 leaves with 4-8 pairs of pinnae, each pinna bearing 6-12 pairs of 

 oblong small leaflets, with a gland situated on the petiole be- 

 tween the lower pair of pinnae ; heads of flowers pedunculate, 

 crowded, axillary. Jj . S. Native of the East Indies, in woods. 

 Roxb. cor. 2. t. 199. Flowers yellow, polyandrous. Legume 

 linear, a little twisted, 8-10-seeded. Spines white, 1-2 inches long. 



/uory-thorned Acacia. Clt. 1792. Shrub 5 to 6 feet. 



176 A. TORTUO'SA (Willd. spec. 4. p. 1083.) spines twin, con- 

 nate, and are, as well as the branches and petioles, pubescent ; 

 leaves with 2-6 pairs of pinnae, each pinna bearing 12-16 pairs 

 of leaflets, with a gland between the lower pair of pinnae, 

 and sometimes between the extreme pair ; heads of flowers 

 solitary, axillary ; legumes compressed, thickish, pubescent, 

 rather corniculate. lj . S. Native of Jamaica, in sandy fields, 

 and of the island of St. Thomas. Mimosa tortuosa, Lin. spec. 

 1505. Swartz, obs. 391. but not of Burm. Spines inch long, 

 white, downy at the base. Legumes with fleshy juicy valves. 

 Heads of flowers yellow. 



Twisted Acacia. Clt. 1824. Shrub 4 to 6 feet. 



177 A. BURMANNIA'XA (D. C. prod. 2. p. 461.) spines twin, 

 glabrous; branches angular, smoothish ; petioles pubescent; 

 leaves with 6 pairs of pinnae, each pinna bearing 15-20 pairs of 

 leaflets ; gland small, petiular ; heads of flowers solitary, on long 

 axillary peduncles, ij . S. Native of the East Indies. Mimosa 

 tortuosa, Burm. fl. ind. p. 224. Heads of flowers larger than 

 those of M. tortuosa. Legume unknown. 



Var. j3 ; peduncles 3-together, axillary. fj . S. Native of 

 the East Indies. Mimosa cae'sia, Burm. fl. ind. 224. but not 

 of Lin. A. Ceylanica sarmentosa flore luteo globoso, Burm. 

 zeyl. p. 3. 



Burmann's Acacia. Clt. 1818. Shrub 4 to 6 feet. 



178 A. VE'RA (Willd. spec. 4. p. 1 085.) spines twin ; branches 

 and leaves glabrous ; leaves with 2 pairs of pinnae, each pinna 

 bearing 8-10 pairs of oblong-linear leaflets, with glands on the pe- 

 tioles, one between each pair of pinnae ; heads of flowers usually 

 twin, pedunculate, axillary ; legume (ex Willd.) moniliform. Jj . 

 S. Native of Africa, from Senegal to Egypt. Mimosa Nilotiea, 

 Lin. spec. 1506. but not of hort. cliff. Woodv. med. bot. 187. t. 

 67. Lob. icon. 2. p. 95. f. 1. Hern. mex. 866. f. 1. Gom- 

 mier rouge, Adans. Branches and spines red. Flowers yellow. 

 This is the tree which yields the gum-arabic of the shops, and 

 succus acaciae. According to Hasselquist the Arabs call it 

 chasad. The gum is gathered in vast quantities from the trees 

 growing in Arabia Petrsaa, near the north bay of the Red Sea at 

 the foot of mount Sinai ; this gum is called by dealers Thur or 

 Thor, which is the name of the harbour in the north bay of the 

 Red Sea, thereby distinguishing it from gum-arabic. The gurn- 

 thur is also more pellucid and white, whereas gum-arabic is of 

 a brown or dirty yellow colour, and generally opaque. 



Gum-arabic is a concrete juice, which exudes from various 

 species of Acacia, but especially from A. vera, A. Ardbica, and 

 A. Senegal, natives of the sandy deserts of Africa, Arabia, and 

 other parts of Asia. It either exudes spontaneously or from in- 

 cisions made in the bark, and afterwards hardens in the air. The 

 barks of all the species are highly astringent, and some are used 

 in India for tanning. There are two kinds of gum found in the 

 shops in this country, and often sold promiscuously, but distin- 

 guished in commerce by the names of gum-arabic and East 

 India gum. Gum-arabic consists of roundish transparent tears, 

 colourless, or of a yellowish colour, without smell or taste, and 

 almost perfectly soluble in water. The pieces which are most 

 transparent and have least colour are reckoned the best. They 

 are sometimes selected from the gum-arabic and sold for about 

 double the price, under the name of picked gum. The East 

 India gum is darker coloured than gum-arabic, and is not so 

 readily soluble in water. Gum-thur, the produce of Acacia 

 Arabica, is almost colourless, and resembles the picked gum, and 

 gum-senegal resembles the East India gum. 



About the middle of November, that is, after the rainy season, 

 which begins early in July, a gummy juice exudes spontaneously 

 from the trunk and principal branches. In about 15 days it 

 thickens in the furrow down which it runs, either into a vermi- 

 cular shape, or more commonly assuming the form of round or 

 oval tears, about the size of a pigeon's egg, of different colours, 

 as they belong to the white or red gum tree. About the middle 

 of December the Moors encamp on the borders of the forest, 

 and the harvest lasts 5 weeks. The gum is packed in very large 

 sacks of tanned leather, and brought on camels and bullocks to 

 certain ports, where it is sold to the French and English mer- 

 chants. Mr. Jackson, in his account of the empire of Morocco, 

 informs us, that from Mogodor they export two sorts of gum, 

 one is common gum-arabic, the other finer, called gum-soudan, 

 brought from Tumbuctoo by the caravans. He also says that 

 the gum called Morocco or Barbary-gum, is produced from a 

 thorny tree called Atlaleh. It yields most gum during the parch- 



